Clutch



` sept. s, 1936. B T SEBIRE y 2,053,376

' CLUTCH original Filed June 2, 1935 a 14 if 277057721611', Berg/amv?Zz/'e l MEET Patented Sept. 8, 1936 Fries PATENT 2,053,376 CLUTCHBenjamin T. Sebire, Ashland, Mass., assignor of fifty-two one-hundredthsto Charles E. Marshall, Hopkinton, Mass.

original application .June 2, 1933, serial No. 674,079. Divided and thisapplication January 23, 1935, Serial No. 3,077

c claims. (cl. '14g-411) The present invention relates to an automaticclutch mechanism and particularly to a clutch which is automaticallyreleased when the torque von the driven shaft reaches a predeterminedpoint, thereby avoiding overloading of the driving element. Thisapplication is a division of the copending application Serial No.674,079, led June 2, 1933, for an Electric door, closer.

i The provision of a clutch which is automatically released when thetorque on the driving shaft reaches a predetermined maximum limit isparticularly desirable inmany clutch installations,`

as for example, in a door opener and closer where the door may beVmanually opened at a different rate from the normal rate of openingy orclosing of a door by the driving motor. If no provision were made fordisengaging"` the driving motor from the door, said motor would .beoverloaded and damaged. It is accordingly one of the principal objectsof the presentinvention to provide a clutch mechanism which isautomatically released to prevent overload onV the driving member in theevent that the normal operation of the driven mechanism is in"terrupted.

The present invention further provides in a clutch of this type, for theautomatic reengagement of said clutch mechanism when normal operation ofthe' driven structure is again possible, and further provides for apositive actuation of the driven structure so long as said driven strucline 4-4 of Fig. 1.r Fig. 5 is a vertical section along the line 5-.iy

of Fig. 4.

Like reference characters refer to like partsin the; different figures.

The clutch of the invention is `shown in con-v nection with anelectrically actuated door open? ing and closing mechanism whichinvolves a driving motor I secured to the frame 2 of the mechanism,Ysaid motor having a shaft 3 to the end offwhich the gear 4 is secured.Said gear is in mesh with a gear 5 on the end of a shaft 6 journalled ina portion of the frame 2, and the opposite end of the shaft 6 carries aWorm 1 which meshes with a worm gear 8 secured` against turning movementon a vertical shaft l z iournalled in bearings II and I2 in the frame. l

bracket I3 secured to the frame supports a bearing I4 for the upper endof the shaft ID.

A sleeve I5 surrounding the shaft I0 has a slot engageable with a pin I6in said shaft, whereby said sleeve has a limited axial movement on thepin, but is held against turning movement thereon. The lower end of thesleeve has cogs I8 whichV engage with corresponding cogs 2|) on a bevelgear 2l rotatable on the shaft I0 and held against downward movement byengagement with the* hub worm gear 8. The bevel gear 2| meshes with abevel gear 24 journalled on a stub shaft 25 secured to the frame 2.

Cogs 26 on the upper end of the sleeve I5 en-V gage, when the sleeve isin its upper position, with corresponding cogs 21 on a bevel gear 28secured to a sleeve 3| surrounding the shaft I0. The bevel gear 28 is inmesh with the bevel gear 24 above referred to.

The sleeve I5 is connected selectively to the bevel gears 2| or 28 bysliding movement of said sleeve on the shaft. To this end the sleeve I5has an annular groove 33 engaging with pins 34 and 35 on arms 36 and 31which are journalled at one end on a horizontally extending bolt 33secured to the frame. The opposite ends of the arms are connected toeach other by a pin 40 which also supports one end of a link `4I throughwhich the sleeve I5 may be automatically shifted by suitable mechanism,which is not a feature of the present invention and will not be furtherdescribed. It is sufficient to note that the drive for the actuation ofrthe device is through the sleeve 3i 'and that the direction of rotationof this sleeve is controlled by the position of the sleeve I5, as willbe apparent.

From the sleeve 3| the drive is through a clutch mechanism, embodyingthe invention, and hereinafter described, to a sleeve 42 having an arm43 secured thereto, as by a set screw 44. The arm 43 is connectedthrough a suitable link, not shown, to the door jamb, the frame 2 beingsecured to the door which is to be actuated by the device. Oscillationof the arm 43 for opening and closing of the door is procured inresponse to turning movement of the sleeve 3|, as will be apparent.According to the present invention the clutch connection between thesleeve 3| and sleeve 42 is such that the door may be manually opened orclosed at a rate different from its normal rateof movement as a resultof the rotation of the motor I, and the clutch provides for automaticrelease thereof to prevent damage to the parts of the device when thedoor is so opened and closed, or held against opening or closingmovement while the motor I is in operation.

Referring now to Figs. 1 and 2, the sleeve 3| which surrounds the shaftIIJ extends upwardly through the bearing I2, the latter engaging withaxial movement on the member 44.

the bevel gear 28 to support said gear against axial movement. Anannular member 44 is axially slidable on the sleeve Yand is held againstturning movement by a key 45. A plurality of cogs 48 on the lowersurface of the member 44 engage the corresponding cogs 41 on the hub ofa gear 48 journalled on the sleeve. Beneath the gear 48 is journalled asimilar gear 58 having a large diameter hub on the upper surfacethereof, the underside of the gear 58 engaging with the upper end of thebearing I2 to prevent axial movement of said gear on the sleeve.

V-shaped notches 5I are provided on the upper end of the hub of the gear58 for engagement with the ends of lugs 52 depending from a plate 53having a semi-circular recess 54, Fig. 3, which receives the member 44.The latter has an annular groove 55 with which said plate is engageable,said plate being supported by said groove against The lugs 52 projectdownwardly through openings 55, Fig. 4, in the gear 48 for engagementwith the notches 5I. A spring 51 which surrounds the sleeve 3| betweenthe member 44 and a collar 58 secured to the upper end of the sleeve,normally holds the cogs 46 and 41 in engagement. A relative turningmovement between the gears 48 and 50 will withdraw the lugs 52 from thenotches 5 I1, elevating the member 44 to separate the cogs 48 and 41,and thereby permitting the sleeve 3| to turn without providing acorresponding rotation of the gears 48 and 58. Y

The gears 48 and 58 are in mesh with similar gears 68 and 6|respectively, on a vertical stud 82 secured'to the frame. The gear 8| isintegral with the sleeve 42 which extends upwardly from said gear. Thegear 88 is journalled on the sleeve` a similar projecting pin 65 whichextends through an arcuate slot 86 in the gear 88, the pins` 64 and 65being normally retained in radial alinement.

To this end, as shown in Fig. 4, the gear 68 has spaced upwardlyprojecting studs 61 and 68 on which areI journalled arms 18 and 1 I.Saidarms extend around the sleeve 42 and are provided with opposedparallel surfaces adjacent the freeends thereof for engagement with thepins 64 and 65. A second arm 12 which is pivotally mounted onthe stud 61has a set screw 13 in. an upwardly projecting lug 14 for engagement witha lug 15 on the arm 18. A spring 16 is. connected at opposite ends toupwardly extending lugs 1.1

and 18 on the arms 12 and 1I respectively, andv said spring normallyurges said arms 10- and 1I toward each other. The tension of the spring16 which determines the amount of pressure. ex-

erted by the arms 18 and 1I on the pins` 84 and..

65 for retaining said pins in radial alinement is adjusted by turningthe set screw 13, thereby varying the relative position of the arms 18and A vertical stud 83, Fig. l, supported by the frame 2, has a gear 84journalled thereon for engagement with the gear 48. A sleeve 85 of brousor other irictional material surrounds the stud 83 below the gear and isheld against turning movement on said stud, the end of said sleeveengaging with the hub of the gear 84. A spring 86 surrounding the stud'I3l above the gear engages at its lower end with a washer 871 suitablyheld vagainst rotation on the Stud and engaging with the upper end ofthe hub of the gear 84. A knurled nut 88 engages the'upper end of thespring and is in threaded engagement with the upper end of the stud 83,turning movement of the nut 88 providing for varying the tension of thespring 86 for a greater or less braking action between the gear 84 andthe frictional sleeve 85.

The gearing above described, including the gears 48- and 50, andthegears 68 and 6| meshing therewith, as well as the gear 84 which acts asa brake, constitutes an automatic clutch which will Permit the arm 43 toturn independently of the motion of the vertical shaft I8 or of thesleeve 3 I. The rotation of the member 43, the direction of which. isdeterminedby the position of the sleevev I5, isnormally transmitted tothe gear 48 through the Cooperating cogs 46 and 41, the rotation of thegear 48- procuring a corresponding rotation 0f the gear 68. The rotationof the latter is. transmitted through the pins 84 and |35` to the gear6IA having the integral sleeve 42 to which the arm 43 is secured.

The. tension of the spring 16 is normally great enough tov transmit therotation of the gear 68 to the gear 6I without permitting any relativeturning movement-between said gears. With theA gears 60 and 6| turningin unison with the pins 64 and 65in radial alinement, the gears 48 and58 also rotate together so that the depending lugs 52 remain inengagement with the notches 5I in the gear. 50 and the cogs 46 and 41accordingly remain in, engagement with each other. During the. positiverotation of the member 44 from the driving motor the gear 84, which actsas a brake, is driven. directly from the gear 48 and has no eiect on`the relative positions of the gears 48 and 5|l. Itr willbe apparent thatif the sleeve 42V beheld against turning movement, the motor willcontinue to turn the gear 60 until the pins 64 and 65 are out ofradial-alinement, thereby turning the gears48 and. 50..relative to eachother for elevating, the plate 53, and accordingly with'- drawingAthelcogs 46v outY of engagement with the cogs 41 to. permit a continuedrotation of themetor I without any corresponding movement of the arm 43.

The same operationtakes place when the arm 43 is rotated. manually at adifferent speed than the normalrate. of. movement thereof, the cogs 48and' 41 being automatically withdrawn from engagement with each otherto: permit a relative turning, movement. of the arm 43Y relative to thedriving mechanism. IoI procure this action the turning, movement of4 thearm 431procures a corresponding turning movement of the gear 6I and. aturning movementv of the gear 58 whichmeshes therewith.. The gear 48.,however, is held resiliently against turning movementV by the brakinggear 84.the tension of the spring 86 being such that the gears 6U and 6I will turn relative to each other againstthe-tension of the spring 18.Since the gear 48 is held against turning movement andthe. gear 58 ispositively rotated from the gear 8|.. a. relative turning movementbetween the gears48 andll takes place, thereby elevating theplate.l 53toseparate the cogs46 and 41. The arm 437 may then be'shifted in eitherdirection whether or notthe motor I. is4 in operation.Y

When. the-arm.y 4-3 is no longer being movedr at an. abnormalrate of`speed, or when said arm is brought to` rest when the motor lf is` atrest, the. spring 16-urges the arms 18 and 1I together to' re-alinethe-pins 64 and 85 forl reestablishing the original relation betweenthegears 48 and present invention provides a clutch which isautomatically released under an overload, or is automatically releasedwhen the driven structure is moved at a rate of speed other than thenormal rate of speed at which the device is intended to be driven. Theclutch moreover automatically reestablishes the positive drivingconnection between the driving and driven elements when the drivenstructure is again capable of normal operation. The device provides forautomatic release of the clutch when the driving element is stationaryand the driven element is actuated by external means.

I claim:

l. In a clutch mechanism, a driving member, a driven member, and aclutch element for procuring a positive turning movement of the drivenmember, the latter comprising a pair of coaxial rotatable members, meansfor positively connecting one of said members to the driven member,clutch means connecting said other ro.- tatable member releasably to thedriving member, means for resiliently holding said rotatable membersagainst a relative turning movement, and means responsive to a relativeturning movement of said rotatable members for disengaging said clutchmeans to provide for relative movement between the drivingv member andthe rotai-able member connected thereto, said resilient means providingfor returning said rotatable members to original relative position forreestablishing the connection between the driving member Y and rotatablemember connected thereto.

2. In a clutch mechanism, ar driving member, a driven member, and aclutch element for procuring a positive turning movement of the drivenmember, the latter comprising a pair of coaxial rotatable members, meansfor positively connecting one of said members to the driven member,clutch means'connecting said other rotatable member releasably to thedriving member, means for resiliently holding said rotatable membersagainst a relative turning movement for rotation of the driven member,in response to rotation of the driving member, means for applying apredetermined braking action to said other rotatable member, and meansresponsive to a relative turning movement of said rotatable members fordisengaging said clutch means to provide for a relative movement betweenthe driving member and the rotatable member connected thereto, saidbraking action procuring a relative turning movement of said rotatablemembers against the action of the resilient means which normally holdssaid members against relative turning movement, whereby the drivingmember is disengaged from said other rotatable member when the drivenmember is rotated at an abnormal rate of speed.

3. In a clutch mechanism, a driving member, a driven member, and aclutch element for connecting said members together, said elementcomprising a pair of coaxial gears, a clutch by which one o-f said gearsis releasably connected to the driving member, a second pair of coaxialgears meshing with said first pair of gears, means for positivelyconnecting one of said second pair to the driven member, resilient meansfor normally supporting said second pair of gears against relativeturning movement, and means responsive to a relative turning movement ofthe rst pair of gears for disengaging the clutch to release the drivingmember from the gear connected thereto, said resilient means associatedwith the said second pair of gears again providing for a relativeturning movement when the driven member is not moved at the normal rate,thereby disengaging the driving member from the gear connected thereto.

4. In a clutch mechanism, a driving member, a driven member, and aclutch element for connecting said members together, said elementcomprising a pair of coaxial gears, a clutch by which one of said gearsis releasably connected to the driving member, a second pair of coaxialgears meshing with said rst pair of gears, means for positivelyconnecting one of said second pair to the driven member, resilient meansfor normally supporting said second pair of gears against relativeturning movement, and means responsive to a relative turning movement ofthe first pair of gears for disengaging the clutch to release thedriving member from the gear connected thereto, said resilient meansconnecting said second pair of gears again providing for a relativeturning movement when the driven member is not moved at the normal rate,thereby disengaging the driving member from the gear connected thereto,and'means for applying a braking action to the gear to which the drivingmember is releasably connected to hold said gear against turningmovement whereby said driving member may be disengaged from said gearwhen the driven member is rotated at a speed other than its normal rateof movement as determined by the driving member.

5. In a clutch mechanism, a driving member, a driven member, a pair ofco-axial gears, a releasable clutch providing a connection between oneof said gears and the driving member, a second pair of co-axial gears,meshing with said irst pair, means for positively connecting one of saidsecond pair to the driven member, means responsive to a relative turningmovement of said iirst pair of gears for procuring disengagement of saidclutch, and resilient means normally preventing relativeturning movementof said second pair of gears to retain the clutch in engagement, saidresilient means also returning said second pair of gears to originalrelative position after a relative turning movement thereof forrestoring the clutch vto operative position.

6; In a clutch mechanism, a driving member, a driven member, a pair ofco-axial gears, a releasable clutch providing a connection between oneof said gears and the driving member, a second pair of co-axial gears,meshing with said first pair, means for positively connecting one ofsaid second pair to the driven member, means responsive to a relativeturning movement of said first pair of gears for procuring disengagementof said clutch, resilient means normally preventing relative turningmovement of said second pair of gears to retain the clutch inengagement, said resilient means also returning said second pair ofgears to original relative position after a relative turning movementthereof for restoring the clutch to operative position, and means forapplying a braking action to the` gear of the first pair which isconnected by the clutch to the driving member.

BENJAMIN T. SEBIRE.

